Logion 103 alludes to rebels attacking, and I understand that in this vein. It is a theme that is also very prevalent in the Course, fundamentally meaning that we should understand what the ego is all about so that we can choose against it. This comes back in the constant admonitions to look at the ego with Jesus, for the way the ego (the rebels) loses power is because its mode of operation becomes exposed. It can not stand the light of day, and certainly not the light of forgiveness. The minute we lose the fear of the ego, and no longer take it seriously, that is the moment when we slip out of the vise-grip in which it has been holding us for too long while we gave it credence.
So, we need to know enough to see where the attack is going to come from, so that you will not be surprised by the attack, here is the same warning in the words of the Course:
You, then, have two conflicting evaluations of yourself in your mind, and they cannot both be true. You do not yet realize how completely different these evaluations are, because you do not understand how lofty the Holy Spirit's perception of you really is. He is not deceived by anything you do, because He never forgets what you are. The ego is deceived by everything you do, especially when you respond to the Holy Spirit, because at such times its confusion increases. The ego is, therefore, particularly likely to attack you when you react lovingly, because it has evaluated you as unloving and you are going against its judgment. The ego will attack your motives as soon as they become clearly out of accord with its perception of you. This is when it will shift abruptly from suspiciousness to viciousness, since its uncertainty is increased. Yet it is surely pointless to attack in return. What can this mean except that you are agreeing with the ego's evaluation of what you are? (ACIM:T9.VII.4)Given that we do recognize the ego for what it is, and are not taken in by it, we are then in a position to return the dream of fear to its maker, and to hear that it was not a big serious sinful idea, but a silly mistake, while our biggest problem was not entertaining a stupid thought, but taking it seriously, so Jesus offers humor as the avenue to diffuse the whole thing. Thus one part is to realize that the ego is fully up to no good, and to face that for what it's worth, but secondly not to take that seriously at all, by asking Jesus's help to laugh it away with him. The silliness of it all undercuts the grip the ego has on us.
Let us return the dream he gave away unto the dreamer, who perceives the dream as separate from himself and done to him. Into eternity, where all is one, there crept a tiny, mad idea, at which the Son of God remembered not to laugh. In his forgetting did the thought become a serious idea, and possible of both accomplishment and real effects. Together, we can laugh them both away, and understand that time cannot intrude upon eternity. It is a joke to think that time can come to circumvent eternity, which means there is no time. (ACIM:T-27.VIII.6)